Moving Home folder from internal to external hard drive: Issues on Mac mini M4 Pro

sleepymd wrote:

The advisor did say that there was an internal support article suggesting that there may be security issues with moving this off the internal HD, which may preclude changing your Home folder. He was not sure if this was an M4 issue as I brought up that the internet has many people doing moving their Home folder to an external drive. They are supposed to get back to me with any solutions.

Regardless, I wanted to see if the community had any thoughts or solutions? At the very least I wanted to share my experience.

Moving the Home folder to an external drive is probably not formally supported by Apple. This has been debated here many times. Apple does have instructions for renaming one's Home folder. But physically moving it to an external drive is much more involved and is not actually mentioned explicitly in Apple's documentation. So you are sort of on your own if you want to do this. From what I have seen in the Discussions, this has worked in the past, then periodically it is broken by a new MacOS or MacOS update, then maybe is re-enabled at some point, but typically breaks down again. It does not seem to be a reliable thing. People who have moved their Home folder to an external drive seem especially vulnerable when there are Security Updates, MacOS updates, or MacOS upgrades later on. The consequence when this fails is severe because it can mean the user cannot log in or access their files anymore. Or other odd behaviors result. Putting iCloud storage into the mix makes it even more fragile, especially when there are future MacOS updates.

Apple's increasing posture on security has made it harder and harder to do things like this, especially recently and with the latest Mac models.

Etresoft has made some recent posts on this topic in which he explained better than I can why this is not a reliable approach (moving one's Home folder to an external drive).

To save storage, you can move your Music and Photos libraries to external drives, and Apple has clear instructions for doing that. Also, in iCloud Photos, you can elect to have only small thumbnails physically stored locally while the full size files are placed in the cloud, hence saving considerable local storage space. I have seen posts here where users boast about moving virtually everything they have to iCloud and still able to function on Macs with tiny internal storage (128 GB or 256 GB).

Personally, I do not utilize iCloud to offload storage from my Mac or iPhone, I use it to effortlessly synchronize between multiple devices (Macs and iPhones), e.g. Messages, Photos, Contacts, Safari, etc. I would literally prefer to pay upfront for more internal storage (and Apple charges a lot for that) when purchasing a new Mac than be struggling for years to find a way to get things to fit.

I would never move my Home folder to an external drive because (a) I think it is not a reliable approach, and (b) the logistics seem complex for backing up both the internal and now external Home drives with Time Machine in a way that makes recovery reliable and bulletproof; this also makes migration to a new Mac in the future problematic as you would need Setup Assistant or Migration Assistant to know to retrieve some files from the internal drive and others from an external drive. Or somehow find them on a Time Machine backup that has some convoluted set of backup snapshots from this melange.

What you've been told is that it is very difficult and risky to move the home folder to an external drive. It was difficult with Intel Mac and even more so with Silicon Macs.

A safer and easier method to do that is to copy the Pictures folder to the EHD. Once the copy is complete and verified erase the contents of the Pictures folder. Do the same for the Documents, Movies and Music folders.

Then remove those same folder from the Finder's sidebar and drag the same folders from the EHD into the sidebar. I kept both the internal and external Pictures folders in the sidebar with my new Mini as I wanted a couple of my most used Photos libraries to be on the boot drive for speed reasons.

The only folders in the Home folder you need to keep on the internal drive is the Applications, Library, Shared, Downloads and Public. Actually the Photos, Documents and Music are the only ones that need to be moved for storage sake. They are the ones you fill up the most.

sleepymd wrote:

Regardless, I wanted to see if the community had any thoughts or solutions?

Moving your home directory, or that of any user account, is one of the riskiest things you can do and will probably corrupt your system now or at some unexpected point in the future. Just don't do it.

Move things that are known to take up a lot of space. These are easy to relocate and there are documented instructions about how to move them:

• Photos Library
• Music Library
• iMovie Library
• TV Library
• Final Cut Library
• etc.

Create your own Documents folder & Downloads folder on the external drive and use them to store your user documents & other files, not the default Documents & Downloads folders that are in your user home folder.

sleepymd wrote:

I'm worried my iCloud storage will at some point exceed what is on the internal HD

iCloud is designed to do exactly that.

I have been reading many articles and Youtube video on this

That's unfortunate. The internet is usually wrong.

in theory this should be possible and even supported by Apple.

I think it is possible, but it definitely isn't supported by Apple.

Created a APFS volume on an external SSD

You will also have to make sure to enable ownership on the external drive.

Copied the home folder from the internal HD to the external HD

How did you do that? There is only one way to do it properly, and that doesn't even mean it will work.

First, you have to log out of the account being moved. Then, under your administrator account, copy the home directory to the external drive. I recommend using the Terminal with the "cp" or "ditto" command-line tools and the appropriate options. You will need to use both the "sudo" command and make sure that Terminal has Full Disk Access.

If it fails on some "Caches" directory, you can just manually copy the rest of the directories. But if that happens, said "Caches" directory is definitely corrupt, so you should delete it on the external drive.

Probably the most likely method to copy a home directory would be just after creating it. At that point, before you've ever logged in, there won't be any caches folder.

Created a separate user account with admin privileges.

Does this mean that you didn't do that on the first attempt? Not a single internet article or Youtube video mentioned this absolutely critical step? This why people should stay off the internet.

You absolutely must have an admin account that exists only on the internal drive. You will need to use that account when (not if), your external home directory stops working.

I also strongly recommend logging in to the admin account after restarting. That will make sure the external is correctly mounted before you attempt to log in with the other account. Log out of the admin account and then login to the external account.

Note that you will suffer from a 2x to 10x performance hit, depending on the external drive. Why spend so much money for Apple's super-fast internal SSD and then using an external that is much less reliable and much slower.

I'll leave it to the tech gurus but my two cents would be to keep it simple, if you have space concerns then find some datasets that can naturally sit on external storage without impacting performance and regardless of where your 'home' directory is. ~/Library is a blackhole of caches, logs, configs, cloud sync, mail etc that I would avoid tangling with (I think there's a reason ~/Library/Mobile Documents is hidden on 2 levels).

It also depends how much space utilization you are dealing with, or are just thinking for the future. Personally I keep all my documents, music, default photos library, Lightroom catalog on local disk as this stuff I access daily, it takes up 350Gb out of 1Tb which is fine for me. If you use Apple Music then check the downloads as those are another space hog that can be optimized. My TB's of raw photo data, audacity projects etc I store on external disk. iCloud I only use for things that truly need to be shared between devices (config, iPhone photos, specific documents). I have not found iCloud to be good as a "cloud backup", it's really designed to be a primary file location and then sync's locally to that doubly hidden directory so it doesn't save local storage unless you optimize that and just trust your data to iCloud. For cloud backup across all this I use BackBlaze.

I have 20k photos and 1k videos in my photos library from iPhone syncing and it's apparently now 100Gb in iCloud and the default photos library is 65Gb which is probably as large as I want all that to get and will be starting to consider offloading some of that as large photos libraries are another blackhole that become very difficult to deal with and get out of. So if you're concerned about cloud photos consuming your 1Tb local storage, it's probably worth looking into that utilization/strategy to begin with.

Hope this perspective helps. Happy Holidays and enjoy your new Mac Mini!

tbirdvet wrote:

Good suggestions. Also you can set downloads in Safari preferences to the external drive to also save space on the internal.

Several people have reported that this doesn't work in Sequoia. Sequoia does the NSDocument temp-and-switch atomic write and that seems to confuse network volumes and external volumes.

Good suggestions. Also you can set downloads in Safari preferences to the external drive to also save space on the internal.

From what I have read you are just asking for trouble

Downsides to relocating home folder

With a home folder on an external drive:

• Reduced speed—external drives even the fastest are about half the speed of Apple’s internal SSDs, though this might change with the advent of Thunderbolt 5.
• Doubled failure possibilities (or worse) that could prevent login—external drive could fail or have a bad cable or a corrupted file system, some RAID-setup incompatibility that arises, etc. Create a separate admin account on the internal drive, just in case.
• Encryption of home folder (important) — can an encrypted drive be unlocked (required) prior to logging in? (not sure)
• Risks— Apple does a poor job testing unusual scenarios (if at all), and moving the home folder is probably a 1 in 50K situation. Risks rise as more complex macOS features are added.
• 
  

Not scalable and makes little sense anyway

I've only ever changed my Downloads folder to the iCloud Drive - I did that by creating a Downloads folder in my iCloud Drive, deleting the original Downloads folder, and then a symbolic link to the iCloud Downloads folder. It seems to work well, the only issue I had was that macOS will switch it back and create another Downloads folder {at least it did with Sequoia), but I overcame that with a sunlnk flag. Though I've heard of people having a problem with that setup, I haven't run into a problem with the Downloads folder.

As for the entire home folder, I think if anything would surely have a problem, it would be the ~/Library folder - a lot of programs set up links to other parts of the system in that folder, some from the /Applications folder or the /Library folder, and if they're using hard links, things will break when you move them to an external disk.

Plus, unless you have a TB drive doing 40Gbps, you're going to have a less responsive system, since many applications make use of the user's Library folder.

I'm worried my iCloud storage will at some point exceed what is on the internal HD

iCloud is designed to do exactly that.

Problem is, that iCloud-only documents are no longer searchable. To do that, they need to be local. Hence the external drive, if your iCloud storage exceeds the internal drive.

Zurarczurx wrote:

You know you're on the internet, don't you?

Ah, the irony! But seriously, this isn't quite "the internet" in the same way. While it's pretty much Apple's only social media venue, it isn't like any other social media venues. It's very difficult to monetize, for one reason. I think I'm one of the only people to have ever pulled it off.

By luck or by design, I think the Apple moderators have done an excellent job of keeping this site more of a throwback to the old internet where truth and accuracy were more valued than followers, likes, and influence. If you really spend a lot of time here, it's kind of fascinating really.

Sometimes "honey pot" threads will develop and those will function more like modern social media. They're almost like little cancers in the forum. But they stay true to their name and keep the rest of the community relatively more healthy.

Zurarczurx wrote:

"That's unfortunate. The internet is usually wrong."

You know you're on the internet, don't you?

Hello~ You’re speaking to a member who knows nearly everything…most definitely where they are.

~Katana-San~

"That's unfortunate. The internet is usually wrong."

You know you're on the internet, don't you?